Tamping machine



Filed March 23, 1965 J. J. HASCH' 3,332,456

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S V! E N WK o H w A u H I Y B E 9 a TQM United States Patent 3,332,456TAMPING MACHINE Joseph J. Hasch, 516 Bush Hill Road, Manchester, Conn.06040 Filed Mar. 23, 1965, Ser. No. 442,129 2 Claims. (Cl. 14173) Thisinvention relates to powder filling and tamping devices, and moreparticularly to an improved tamping device for filling and tightlytamping bronze, silver, or similar types of powders into the confines ofa relatively fragile retainer without breakage of said container.

The main object of the invention is to provide a novel and improvedtamping machine which is relatively simple in construction, whichprovides an accurately controlled filling and tamping action, wherebypowdered material, such as bronze, silver or similar powdered substancesmay be admitted into and tamped within a relatively fragile retainerwithout risk of breakage of the retainer, and which is operatedpneumatically from a suitably timed air supply.

A further object of the invention is to provide an improved powderfilling and tamping device for filling and tightly tamping bronzepowder, silver powder, or other similar types of powder into carbonbrushes, the machine being relatively inexpensive to fabricate, beingdurable in construction, and being self-clearing in action so that it isnot easily clogged by the material being processed.

A still further object of the invention is to provide an improved powderfilling and tamping device for filling and tightly tamping powders intosuitable containers, the device being able not only to fill and tampmaterial into an unfilled cavity, but to continue to fill and tamp, withequal force, a partially filled cavity, the device continuing to tampwith substantially unchanging force even though the length of itsplunger stroke continues to be reduced as the height of the tampedmaterial in the container or cavity increase-s, whereby the material issubstantially uniformly packed in the container or cavity and wherebythe tamping force is always sufiicient to provide uniform packingdensity of the material but is never high enough to cause breakage ofthe receptacle in which the material is packed.

Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompanyingdrawings, wherein:

FIGURE 1 is a perspective view of an improved powder filling and tampingmachine constructed in accordance with the present invention.

FIGURE 2 is an enlarged vertical cross sectional view takensubstantially on the line 22v of FIGURE 1.

FIGURE 3 is a vertical cross sectional view taken through a modifiedform of powder filling and tamping machine in accordance with thepresent invention.

FIGURE 4 is a horizontal cross sectional view taken substantially on theline 44 of FIGURE 3.

FIGURE 5 is a fragmentary vertical cross sectional view of the lowerportion of the machine shown in FIG- URE 3 with the plunger elementthereof in depressed tamping position.

Referring to the drawings, and more particularly to FIGURES 1 and 2, 11generally designates an improved powder filling and tamping deviceconstructed in accordance with the present invention. The device 11comprises a support 12 consisting of a horizontal base plate 13 to whichis rigidly secured an upstanding vertical supporting post 14. The post14 rigidly supports a vertical sleeve 15, the sleeve being integrallyconnected to the post by a pair of spaced horizontal supporting bars 16,16, whereby the sleeve 15 is rigidly sustained in spaced parallelrelationship to the upstanding vertical post member 14, as is clearlyshown in FIGURE 2.

3,332,456 Patented July 25, 1967 Adjustably secured within the sleeve 15is a cylindrical hopper 17, the hopper being secured in adjustedposition in the sleeve 15 by a manually operated wing screw 58threadedly engaged in the sleeve 15 and being clampingly engageable withthe cylindrical body 17. Secured to the lower end of the cylindricalbody 17 is a downwardly convergent conical spout member 18 in the end ofwhich is secured an annular dis-charge nozzle element 19. The topportion of the cylindrical body 17 is integrally formed with an upwardlyflaring peripheral flange 20 serving to guide material admitted into thetop of the hopper downwardly through apertures 21 formed in a horizontaltop wall 22 provided inside the hopper at the top end of its cylindricalbody 17. The lower portion of said cylindrical body is similarly formedwith a horizontal partition wall 23 formed with apertures 24 throughwhich the material, shown at 25, may pass downwardly by gravity into theconical spout member 18.

Designated at 26 is an axial sleeve which is provided inside the body17, said sleeve being formed integrally with and being supported by thetop and bottom partition walls 22 and 23, as is clearly shown in FIGURE2. Designated at 27 is a conventional air hammer which is provided witha reciprocating plunger 28, said plunger extending through the sleeve 26and being slidably supported therein by spaced annular bushings 29 and3tl secured to the sleeve 26. As shown in FIGURE 2, the bushings 29 andare spaced vertically sufliciently to guide the plunger 28 for axialreciprocating movement in the sleeve 26. The bushings 29 and 30 aresecured in fixed positions in the sleeve 26 by set screws 31 and 32threadedly engaged through the wall of sleeve 26 and clampingly engagingthe bushings 29 and 30.

The air hammer 27 is provided with the downwardly tapering lower barrelportion 33 which extends into the top end of the sleeve 26 and which isrigidly secured thereto, as by welding, brazing, or the like, as shownat 34. Secured on the downwardly tapering member 33 is an annularoutwardly extending upwardly diverging skirt member 35 provided with theupstanding peripheral flange 36, the skirt member 35 overlying thepowder intake chamber defined by the upwardly flaring top member 2t} ofhopper 17.

Threadedly secured on the lower end of the sleeve member 26 is anannular cup member 37 having a central bottom aperture through whichprojects the reduced, rodlike lower end portion 38 of plunger member 28.The plunger member 28 is formed with an annular bearing flange 39 at thetop end of reduced portion 38, and a coiled spring 40 surrounds saidreduced portion, bearing between the flange 39 and the bottom wall ofthe cup member 37, biasing the plunger 28 upwardly. Thus, as shown inFIGURE 2, the spring 40 biases the plunger member 28 upwardly to aposition wherein the lower end of the reduced plunger portion 38 isspaced above the top end of the central bore of the nozzle member 19,allowing powder material 25 in hopper 17 to gravitate downwardly throughthe nozzle. The base plate 13 supports a block 41 which is provided witha socket or recess 42 arranged so that it is in axial alignment with thenozzle 19, said socket 42 being adapted to receive a relatively fragilepowder receptacle 43, such as a hollow carbon brush, as illustrated inFIGURE 2, thus positioning the receptacle immediately beneath the nozzle19 to receive powdered material, such as copper or silver powder,therefrom. The bore 44 of the receptacle 43 is thus positioned inregistry with the bore of the nozzle 19 and immediately subjacentthereto, as shown in FIGURE 2.

The air hammer 27 is of a conventional type wherein compressed air froma supply hose 45 is introduced into the upper portion of the barrel 46of the air hammer and forces the air hammer plunger 28 downwardly untilan exhaust port (not shown) is opened, at which time air flows throughthe exhaust port and also through the center of the plunger downwardlyand underneath a portion of the plunger so as to return it upwardly andto close the exhaust port. The air hammer 27 therefore operated on aflutter principle, and its rate of reciprocation depends on the pressureof the air supplied thereto and on the natural resonance of the plungermass operating against the compliance of the compressible air. The airhammer 27 in itself is a well known conventional device and the detailsthereof form no part of the present invention.

In operation, the powdered material 25 gravitates downwardly into thebore 44 of the receptacle &3, to fill same. Air is then admitted to theair hammer 27, causing the plunger 28 to be moved downwardly intotamping engagement with the powder in the receptacle 43, the air supplybeing timed suitably so as to provide a sufiicient number ofreciprocations of the reduced plunger portion 38 to compress thematerial contained in the receptacle 'bore 44 to a desired density. Itwill be seen that the recess or socket 42 in the plate member 41supports the receptacie for a substantial portion of its height andserves as as means for absorbing the compression developed therein bythe tamping action of the reduced plunger member 38. Thus, thereceptacle 43, even if made of relatively frangibie material, isprotected against breakage.

Uniform density of the material contained in the receptacle 43 isachieved even though the air hammer 27 is of the rapidly acting typeworking on a flutter principle; this type of air hammer has to have astroke length of substantially constant amplitude applied against asubstantially constant load in order for it to continue to func tion. Inthe apparatus of FIGURE 2, the spring 40 pre sents a load which changeswith stroke length, the spring load cooperating with the load presented'by the material being tamped to provide the required substantiallyconstant load on the air hammer. Thus, effective tamping action isachieved within the fixed frame of the machine over a very considerablerange of stroke length.

As will be readily understood, when the material in the receptacle 43has been sufiiciently tamped, the air supply may be discontinued, andthe spring 40 then elevates the plunger 28 to its uppermost position.The container 43 may then be removed and another container may besubstituted therefor so that the tamping process may be repeated.

The plate member 41 may be removable so that after the material in acontainer 43 has been suitably tamped, the plate member 41 may beremoved so that the filled container 43 may be replaced by an empty one,or alternatively, another plate member 41 containing an empty container43 may be placed into tamping position on the base supporting late 13.

As will be readily apparent, the flange 39 may be integral with theelement 38, and may be separate from the plunger 28, the spring 44)acting to bias the flange 39 against the bottom end of the plunger 28,and the plunger 28 operating to transmit repetitive hammer blows to theflange 39, which are in turn transmitted to the tamping element 38.

FIGURES 3, 4 and illustrate a form of the invention wherein the tampingelement, shown at 33 is separate from the air hammer plunger element28', as above suggested. As shown in FIGURE 3, the tamping element 38'may be formed with an annular flange 50 at its upper portion, and acoiled spring 51 may be provided, bearing between the flange 50 and theupper bearing bushing 29, the spring 51 surrounding the top end portionof the hammer element 38' and the lower portion of the plunger member28. The spring 51 is relatively light and is yieldable to the mainbiasing spring 40 which bears between the bottom wall of the cup member37 and a washer 52 surrounding the downwardly tapering shoulder 53formed on the intermediate portion of the tamping element 38.

The lower portion of the tamping element 38' comprises a reducedrod-like element 54 which extends through the central aperture in thebottom wall of the cup member 37 and which is slidably receivable in thebore of the nozzle member 19' provided at the bottom end of thedownwardly converging spout element 18'.

As in the previously described form of the invention, a plate 41' isprovided, said plate being formed with a socket or recess 42' whichreceives a flanged receptacle 43. The receptacle 43 is formed with acentral axially extending cavity 44 which is registrable with the boreof the nozzle element 19', as shown in FIGURE 3, and which receives thepowdered material 25. As in the previously described form of theinvention, the powdered material is tamped in the cavity 44' to adesired density by the reciprocating hammer action of the rod-liketamping element 54 as the element reciprocates downwardly through thebore of the nozzle 19', the rod-like member 54 descending on itsdownward stroke to a position such as that illustrated in FIGURE 5,wherein the rod-like element enters the top portion of the cavity 44 andis slidably received therein, exerting a downward compressive stroke onthe material 25 contained in the cavity 44. With each downward hammerstroke the spring 40 is compressed, as shown in FIGURE 5, said springacting to elevate the plunger member 38' with each release stroke of theair hammer plunger member 28'. The spring 40 thus acts essentially inthe same manner as in the embodiment of FIGURES l and 2 to cooperatewith the load presented by the tamped powder to maintain a substantiallyconstant load on the air hammer for different stroke lengths, and alsoacts to maintain the top end of the tamping member 38 substantially incontinuous engagement with the bottom end of the plunger member 28, thespring 51 providing a cushioning action to compensate for thedifferences in inertia between the reciprocating elements 28' and 38'and to insure smooth and substantially synchronous reciprocation ofthese elements.

While certain specific cmbodimetns of an improved powder filling andtamping machine have been disclosed in the foregoing description, itwill be understood that various modifications within the spirit of theinvention may occur to those skilled in the art. Therefore, it isintended that no limitation be placed on the invention except as definedby the scope of the appended claims.

What is claimed is:

1. A powder filling and tamping machine comprising a support, a tampingreceptacle on said support, a downwardly convergent hopper on saidsupport having a bottom discharge aperture located over said receptacle,said receptacle being located immediately below said bottom dischargeaperture, a central tubular vertical supporting sleeve rigidly securedin said hopper and having a centrally apertured bottom wall in verticalalignment with and spaced above said discharge aperture, a verticallyreciprocable plunger mounted in said supporting sleeve in verticalalignment with and being slidably engageable in said discharge aperture,pneumatically operated reciprocating means acting on said plunger andhaving a stroke of suflicient length to cause the plunger to engage insaid discharge aperture during the bottom portion of said stroke, anannular bearing member on the upper portion of said plunger, said sleevehaving an annular cup member on its bottom end, and spring meanscontained in said annular cup member and bearing between the bottom endportion of said annular cup member and said annular bearing member andbiasing the plunger upwardly toward a position wherein its bottom end isabove said discharge aperture and presenting a load to the plunger whichincreases with downward movement of the plunger, whereby said springmeans cooperates with material being tamped in said receptacle topresent a substantially constant load to the plunger for differentstroke lengths.

2. A powder filling and tamping machine comprising a support, a tampingreceptacle on said support, a downwardly convergent hopper on saidsupport having a bottom discharge aperture located over said receptacle,said receptacle being located immediately below said bottom dischargeaperture, a central tubular vertical supporting sleeve rigidly securedin said hopper and having a centrally aperturcd bottom wall in verticalalignment with and spaced above said discharge aperture, a verticallyreciprocable plunger mounted in said supporting sleeve in verticalalignment with and being slidably engageable in said discharge aperture,pneumatically operated reciprocating means acting on said plunger andhaving a stroke of suflicient length to cause the plunger to engage insaid discharge aperture during the bottom portion of said stroke, anannular bearing member on the upper portion of said plunger, said sleevehaving an annular cup member on its bottom end, and a coiled springcontained in said annular cup member and surrounding the plunger belowsaid annular bearing member and bearing between the bottom end portionof said annular cup member and References Cited UNITED STATES PATENTS2,331,587 10/1943 Williams 14180 2,400,851 5/ 1946 Steinmueller 14173 X2,437,205 3/ 1948 Middleton et a1. 14l72 X FOREIGN PATENTS 505,464 5/1939 Great Britain.

LAVERNE D. GEIGER, Primary Examiner.

20 H. S. BELL, Assistant Examiner.

1. A POWDER FILLING AND TAMPING MACHINE COMPRISING A SUPPORT, A TAMPINGRECEPTACLE ON SAID SUPPORT, A DOWNWARDLY CONVERGENT HOPPER ON SAIDSUPPORT HAVING A BOTTOM DISCHARGE APERTURE LOCATED OVER SAID RECEPTACLE,SAID RECEPTACLE BEING LOCATED IMMEDIATELY BELOW SAID BOTTOM DISCHARGEAPERTURE, A CENTRAL TUBULAR VERTICAL SUPPORTING SLEEVE RIGIDLY SECUREDIN SAID HOPPER AND HAVING A CENTRALLY APERATURE BOTTOM WALL IN VERTICALALIGNMENT WITH AND SPACED ABOVE SAID DISCHARGE APERTURE, A VERTICALLYRECIPROCABLE PLUNGER MOUNTED IN SAID SUPPORTING SLEEVE IN VERTICALALIGNMENT WITH AND BEING SLIDABLY ENGAGEABLE IN SAID DISCHARGE APERTURE,PNEUMATICALLY OPERATED RECIPROCATING MEANS ACTING ON SAID PLUNGER ANDHAVING A STROKE OF SUFFICIENT LENGTH TO CAUSE THE PLUNGER TO ENGAGE INSAID DISCHARGE APERTURE DURING THE BOTTOM PORTION OF SAID STROKE, ANANNULAR BEARING MEMBER ON THE UPPER PORTION OF SAID PLUNGER, SAID SLEEVEHAVING AN ANNULAR CUP MEMBER ON ITS BOTTOM END, AND SPRING MEANSCONTAINED IN SAID ANNULAR CUP MEMBER AND BEARING BETWEEN THE BOTTOM ENDPORTION OF SAID ANNULAR CUP MEMBER AND SAID ANNULAR BEARING MEMBER ANDBIASING THE PLUNGER UPWARDLY TOWARD A POSITION WHEREIN ITS BOTTOM END ISABOVE SAID DISCHARGE APERTURE AND PRESENTING A LOAD TO THE PLUNGER WHICHINCREASES WITH DOWNWARD MOVEMENT OF THE PLUNGER, WHEREBY SAID SPRINGMEANS COOPERATES WITH MATERIAL BEING TAMPED IN SAID RECEPTACLE TOPRESENT A SUBSTANTIALLY CONSTANT LOAD TO THE PLUNGER FOR DIFFERENTSTROKE LENGTHS.